1. Field of the Invention
The present invention relates to electronic display devices, and, more particularly, to an autostereoscopic electronic display device using a barrier.
2. Description of the Related Art
In electronic displays, a stereoscopic device can provide different images to left and right eyes of a user so that the user can perceive distance and have a stereoscopic sense of the image. An autostereoscopic electronic display is configured to provide a stereoscopic image to a user even when the user does not use an instrument such as polarizing spectacles.
The conventional autostereoscopic electronic display employs a method for space-dividing an image displayed on an image display unit by providing a parallax barrier, a lenticular lens, or a micro-lens array, for example, on the front surface of the image display unit.
The parallax barrier may be formed in a liquid crystal shutter using technologies such as a transmissive type of liquid crystal display. In this case, a mode conversion between a two-dimensional (2D) image mode and a three-dimensional (3D) mode (stereoscopic image mode) becomes possible. As such, the parallax barrier can be effectively applied to a laptop computer or a mobile phone.
Generally, the parallax barrier includes light blocking portions arranged in a stripe pattern and light transmitting portions arranged in a stripe pattern. Therefore, a right eye image realized by right eye sub-pixels reaches the right eye of the user through the light transmitting portions of the parallax barrier, and a left eye image realized by left eye sub-pixels reaches the left eye of the user through the light transmitting portions of the parallax barrier. Accordingly, the user can perceive the image displayed on the image display unit as a stereoscopic image.
However, since the electronic display having the parallax barrier is designed to divide the image into the right and left eye images to display the 3D image, the resolution of the 3D image is reduced to be half the resolution of the 2D image.
To solve this problem, a time-division driving type of electronic display has been developed. The time-division driving type electronic display alternately displays the left and right eye images on the display unit at a predetermined time intervals. In order to realize this, the parallax barrier forms the light blocking portions and the light transmitting portions such that patterns of the light blocking portions and light transmitting portions change with each other. By employing this time-division driving method instead of the space-division driving method, the electronic image display can display the 3D image with resolution that is not deteriorated.
In the time-division driving method, the parallax barrier is required to operate to quickly change patterns of the light blocking portion and the light transmitting portion. Generally, electrodes forming the parallax barrier are alternately arranged to form the light blocking portion and the light transmitting portion. Minute gaps are formed between the arranged electrodes, and therefore light leaks from the gaps. Since the light causes an increase of crosstalk of a 3D image, quality and contrast of the screen are deteriorated.